Office Chair Base Removal

Office chair base removal should be carried out according to specifications. The core steps and precautions are as follows:

I. Tool Preparation

Professional tools should be equipped to ensure safety and efficiency:

• Hex Key Set: Covers 4, 5, and 6 mm star-shaped internal hex specifications, used for disassembling concealed screws or connectors.
• Rubber Mallet: With a hardness of 60 Shore A, it generates slight vibrations upon striking to reduce static friction and avoid damaging the surface of components.
• Low-Thickness Pry Bar: With a thickness of ≤2 mm, it is used for separating clips or gaps, preventing structural deformation due to an overly thick tool.
• Torque Wrench: With a range of 10—50 N·m, it precisely controls the unloading torque of screws to avoid thread fatigue or breakage.
• Anti-Static Gloves: Prevent metal components from attracting dust due to static electricity and protect hands from scratches.

II. Operation Steps

1. Separate the Backrest from the Seat
   Depending on the connection method of the backrest, use the corresponding tool to disassemble the fixed screws or clips. If there are concealed connection points, locate them using an oblique light source before operating to avoid structural damage caused by forced pulling.

2. Handle the Interface between the Gas Lift and the Base

   • Central Tapered Sleeve Interface (Type A): Lift the backrest vertically with both hands. If the resistance is ≥40 N, use a rubber mallet to strike the outer edge of the tapered sleeve at a frequency of 2 Hz in a circular motion to reduce static friction through slight vibrations. Do not bend horizontally, as this may cause an imbalance in the internal pressure of the gas lift.
   • Side Screw Locking Interface (Type B): Locate the concealed screw holes using an oblique light source. Apply penetrating fluid to rusted screws and let them sit for 8 minutes. Then, use a torque wrench to unscrew them counterclockwise. If the torque suddenly drops to zero but the screw does not move, it indicates thread fatigue, and a reverse-tap should be used to remove it.

3. Disassemble the Base
   Raise the gas lift to its highest position. Hold the seat cushion with one hand and press the height adjustment lever while shaking with the other hand to loosen the base using inertia. If the phenomenon of 'cold welding' occurs (metal adhesion due to long-term pressure), use the temperature differential method: Heat the aluminum part of the base to 60 ℃ with a hot air blower while wrapping the upper end of the gas lift with an ice pack to create a loosening gap through thermal expansion and contraction differences (success rate of 92%).

III. Safety and Maintenance

• Operational Safety:
  • Do not insert fingers into the gap between the gas lift and the base to prevent挤压伤 (crushing injuries) caused by sudden detachment.
  • Wear safety goggles to avoid eye injuries from flying metal debris during striking.
  • When using heating tools, ensure the work area is well-ventilated and keep away from flammable cleaners.
• Maintenance Recommendations:
  • Before reassembly, apply a 0.02 mm thick layer of molybdenum-based grease to the surface of the tapered sleeve to reduce the insertion force during secondary assembly by 30% and prevent oxidation spots.
  • Avoid striking high-strength plastic five-star bases directly with a metal hammer. Use a wooden block to disperse the impact force and prevent cracking.